Hand tool for punching holes in a range of plastic irrigartion pipes

ABSTRACT

A cutting tool for forming holes in plastic piping primarily intended for use in holing irrigation pipes for drips and sprinklers ranging from holes with diameter of 2-4 mm. The tool comprises of a blade element made of steel, preferably hardened and provided with a sharpened around cutting edge, and a body and handle made of high strength plastic material, with a lower jaw allowing the holing of pipes ranging from 12-32 mm in diameter.

BACKGROUND OF THE INVENTION

[0001] 1) Field of the Invention

[0002] The invention generally relates to producing holes, and morespecifically relates to a hand tool for punching holes preferably inplastic irrigation pipes of which there are two types. The one leavesthe factory already equipped with drips installed at regular intervalsand the second is a so-called plain pipe that has to have the holespunched in it when the pipe is laid out in the field or garden and havethe drips installed afterwards. The invention relates substantially tothe second type of pipes, although it can be used in connection with thefirst type as well, when there may be necessity to add holes. Theinvention also can be used for producing holes in any flexible plasticpiping. Additionally, subsequent to technological developments newirrigation drip-pipes have been introduced that have internal integraldrips. In this case there sometimes arises the need to add holes or openclogged holes, and with this in mind the invention can cut a precisehole, the depth of which is controlled and therefore prevents cuttingthrough the internal element of the drip-pipe.

[0003] 2). Description of the Prior Art

[0004] The simple hand tool for punching holes in agricultural plasticirrigation pipes with a short handle onto which is affixed a cuttingelement have been known for years. A more advanced punch tool as foundin my invention registered as patent no: 105443, overcame the manydisadvantages associated with the simple tools and provided a reliabletool, although was limited to two pipe sizes only. This presentinvention introduces a tool that has three advantages over the formerinvention.

[0005] a) The cutting element penetrates the pipe in a spiral actionfacilitating the cutting operation.

[0006] b) The tool is suitable for cutting holes in pipes having adiameter between 12 mm and 32 mm.

[0007] c) The depth of penetration of the cutting element can beadjusted according to need thereby adapting the tool to suit also thedrip-pipes with the integral drips.

[0008] These three points show that the present invention is a moreefficient development and advancement on the previous invention.

SUMMARY OF THE INVENTION

[0009] Against the described background it is therefore a main object ofthe invention to provide an improved hand operated tool incorporating init the elements necessary to suit itself to use with a wide range ofplastic irrigation pipes. The other object of the invention is toprovide an improved tool, enabling easy and convenient cutting of holes.An additional object of the invention is to provide a new and improvedtool, which is capable of cutting holes in the so-called integraldrip-pipes without damaging the integral elements, residing within thesaid integral pipes.

[0010] The accompanying drawings, which are incorporated in and form apart of the specification, illustrate preferred embodiments of thepresent invention and together with the description, serve to explainthe principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1: A general cross-section view of the whole tool.

[0012]FIG. 2: The lower jaw with V-shaped support for holding theirrigation pipe.

[0013]FIG. 3: The spiral cutting element.

[0014]FIG. 4: A partial left side view of FIG. 1.

[0015]FIG. 5: A view of the tool at the top end thereof.

[0016]FIG. 6: A partial cross-sectional view of a standard polythelenepipe.

[0017]FIG. 7: A cross-section view of an integral drip-pipe.

[0018]FIG. 8: A general view of the disassembled parts.

[0019]FIG. 9: A general view of an alternative embodiment of the tool ofthe invention.

DETAILED DESCRIPTION OF THE PARTS OF THE TOOL

[0020] With reference to FIG. 1 the main body portion of the tool (1)made of high strength molded plastic material onto which all the otherparts of the tool are assembled. The tool consists of a handle (2), thecutting blade (3), the lower jaw support (7) for the pipe and the screw(8). The screw (8) is made of steel and is 6-8 mm in length. The screw(8) is inserted by pressure through the opening (8A) into the bodyportion (1) and remains fixed without movement. The body portion (1) ofthe tool is built with an opening (1A) such that the fingers of the handcan comfortably hold it and easily pull the handle (1B) that supportsthe lower jaw (7) of the tool during the holing operation. The lower jaw(7) that holds the pipe (10), is formed with prismic-shaped lips (11)and is also made of the same high strength molded plastic material asthe body portion. It is shown in FIG. 2, that these prismic V-shapedlips (11) allow the holding of the said different sized pipes (10A+10B)in such a way that the squashing of the pipe is avoided (this squashingwould make the penetration of the cutting element extremely difficult).This lower jaw (7) part has an adjusting screw-nut (9) also made of thesame high strength molded plastic material, in the center of which is aninternally threaded hole through which the screw (8) passes. Theadjusting screw-nut (9) has a groove (18) in its tip (9A) that ensuresthat the screw-nut (9) sits permanently in the recess (17) made for itin the lower jaw (7) and thus achieving the circular movement. The headof the adjustment screw-nut (9) is shaped with ribs (9B) facilitatingthe turning of the screw-nut (9).

[0021] The cutting element, as seen in FIG. 3 consists of the bladeholder portion (3) and the blade (4) inserted within the holder portion.The cutting blade sits tightly within the holder by virtue of innerlateral protrusions made in the holder (not shown). The blade holder (3)made of the same said high strength molded plastic material, is spirallyshaped with four beginning threads, and carries at its lower part, asteel cutting blade (4). The center part of the blade (4) and bladeholder (3) is hollow allowing the waste plastic that is cut out of thepipes to pass up and out of the upper exit (12). From there the wasteplastic falls out of the space (13) between the handle and the bladeholder. The handle (2) is pivotably mounted on the upper extremity ofthe body portion (1) by virtue of a pin (6), inserted within theopenings (6A+6B), made respectively in the body portion and the handle.The tip (23) of the pin (6), by virtue of its groove (24) ensures thatthe pin will not fall out once inserted in position. The handle (2) ismade with a recess in which the head of the blade holder (3) enters andthus the handle (2) can exert force on the head once the handle ispressed by the hand. The cylindrical head (14) of the spirally shapedblade holder (3) holds the spring (5) in place. The spring (5) returnsthe blade holder (3) to its resting position at the completion of theoperation of the handle. The diameter of the spring (5) is onlyfractionally larger that the blade holder (3) thus ensuring the bladeholder (3) will not bend out of shape after the operation of the handle(2). The cutting blade (4), pressure-inserted into the blade holder (3)is permanent, and is made of hardened tempered and sharpened steel. Thecutting blade is provided with an exit opening (12) larger that theentrance (4A) which allows the cut waste plastic to be releasedimmediately after the holing of the pipe. In the view of the tool shownin FIG. 4, one can see the screw (8) and the recess (25) through whichthe screw (8) enters the hollow center of square side part (26) in thelower jaw (7). In the upper part of the tool, as can be seen also inFIG. 4, there is the entrance (15) of the spirally shaped recess (16)through which the cutting blade (4) and its holder (3) pass through inthe spiral screwing action. The standard plastic irrigation pipe asshown in FIG. 6 is made of polythelene and the hole (22) of size 2-4 mmprovides the place for inserting the dripper (20) into it. The integraldrip-pipe (10C) is shown in FIG. 7 in which the drip (19) is integrallyinside the pipe. The importance here is that during the cutting of theholes (21) the tool must reach only to the integral part and no furtherso as not to damage the integral part of the drip-pipe. In FIG. 9 isseen still a further embodiment of the tool of the invention. In thisembodiment the body (1) portion is not provided with the opening, but isformed with a solid handle portion.

How to Operate the Tool

[0022] When the handle (2) is pressed in the direction of the body (1)of the tool a lever action is created in which the handle (2) presses onthe cutting element (3) causing the cutting element to move down in thedirection of the center of the pipe (10) in a spiral action matching thescrewed position in the body (16) as in FIG. 4. The pipe (10) held inthe lower jaw (7) is supported by the prismic-shaped lips (11). Thedepth of the penetration of the cutting element into the pipe iscontrolled by the adjusting screw-nut (9) that is screwed onto the screw(8). The spirally turning action facilitates the cutting of the hole inthe pipe (10), the cut waste plastic enters the blade and is dischargedup and through the cutting element exiting through the enlarged hole atthe back end of the blade holder (12) and out through the exit (13).

1) A cutting tool preferably for forming a hole in a plastic pipe by ahollow cutting element, capable of penetrating through the wall uponapplying a force thereon, the said tool comprises a) a body portiondefined by a rear grasp portion and by a frontal portion, said frontalportion is provided at its upper extremity with a through-going opening,enabling reciprocating linear displacement of the cutting element fromits uppermost to the lowermost position, said frontal portion is formedwith a through-going bore for a mounting screw, b) a pressure handle,pivotably connected to the upper extremity of the frontal portion, saidpressure handle is adapted to exert force on the cutting element, c) aspring means, situated within the through-going opening made in thefrontal portion, said spring means is capable of returning the cuttingelement from its lowermost postion to the uppermost position, saidspring means is biased upon exertion force on the cutting element, d) asupport member adapted to support the pipe during the cutting, saidsupport member is mountable at the lower extremity of the frontalportion with possibility for sliding there-along, e) an adjustment meansfor controlling the position of the support member with respect to thelower extremity of the frontal portion. 2) The cutting tool as definedin claim 1, in which said cutting element comprises a holder and acutting blade, said cutting blade sits tightly within the holder, saidholder is formed with a head contacting the pressure handle, said headis formed with shoulders contacting the spring means. 3) The cuttingtool as defined in claim 2, in which said holder is formed with a malespiral projection and at least a portion of said through-going openingis formed with a female spiral recess as to ensure, that the cuttingelement rotates during its displacement from the uppermost position tothe lowermost position. 4) The cutting tool as defined in claim 3, inwhich said support member is provided with a V-shaped abutment portion.